
public class Course {

    static  String cno = null;
    static  String pcno= null;
    static  String cname = null;
    static  String grade= null;
    static  String score = null;

    Course(String cno,String pcno,String cname,String grade,String score){
        this.cno = cno;
        this.pcno = pcno;
        this.cname = cname;
        this.grade = grade;
        this.score = score;
    }


    public static void putNull(){
        cno = null;
        pcno = null;
        cname = null;
        grade = null;
        score= null;
    }

    public static Boolean isNull(){
        if (cno!=null){
            return false;
        }else{
            return true;
        }
    }
}
